The subject matter of the present disclosure broadly relates to the art of gas spring and damper devices and, more particularly, to damper rod bushings dimensioned for securement along an associated end member of an associated gas spring and damper assembly and constructed to accommodate pre-loading associated with direct exposure to pressurized gas contained within the spring chamber of the assembly. Gas spring and damper assemblies can include such a damper rod bushing, and suspension systems can include one or more of such gas spring and damper assemblies. Additionally, damper rod bushings in accordance with the subject matter of the present disclosure can be used in connection with methods of manufacturing gas spring and damper assemblies.
The subject matter of the present disclosure may find particular application and use in conjunction with components for suspension systems of wheeled vehicles, and will be shown and described herein with reference thereto. It is to be appreciated, however, that the subject matter of the present disclosure is also amenable to use in other applications and environments, and that the specific uses shown and described herein are merely exemplary. For example, the subject matter of the present disclosure could be used in connection with gas spring assemblies of non-wheeled vehicles, support structures, height adjusting systems and actuators associated with industrial machinery, components thereof and/or other such equipment. Accordingly, the subject matter of the present disclosure is not intended to be limited to use associated with gas spring suspension systems of wheeled vehicles.
Wheeled motor vehicles of most types and kinds include a sprung mass, such as a body or chassis, for example, and an unsprung mass, such as two or more axles or other wheel-engaging members, for example, with a suspension system disposed therebetween. Typically, a suspension system will include a plurality of spring devices as well as a plurality of damping devices that together permit the sprung and unsprung masses of the vehicle to move in a somewhat controlled manner relative to one another. Movement of the sprung and unsprung masses toward one another is normally referred to in the art as jounce motion while movement of the sprung and unsprung masses away from one another is commonly referred to in the art as rebound motion.
Gas spring and damper assemblies are well known and commonly used. Known gas spring and damper assemblies typically include a gas spring assembly and a damper (e.g., a hydraulic or fluid damper). The gas spring assembly can include opposing end members and a flexible bellows or sleeve secured therebetween to define a spring chamber suitable for containing a quantity of pressurized gas. The damper can include a damper housing and a damper piston located within the housing. A damper rod is connected to the damper piston and projects from the damper housing so that the damper piston and rod can undergo reciprocal motion relative to the damper housing.
In an assembled condition, the damper rod and damper housing extend into and through the gas spring assembly. Typically, the damper rod is connected to one of the end members of the gas spring assembly and the damper housing is connected to the other end member of the gas spring assembly. As such, at least a portion of each of the damper rod and the damper housing is typically exposed to the pressurized gas within the spring chamber of the gas spring assembly.
In conventional constructions, a damper rod bushing of a known design will be secured between and operatively connect the end member and the damper rod. Forces and loads experienced during use of the gas spring and damper assembly are transmitted between the end member and damper rod by the damper rod bushing. Additionally, conventional constructions include a seal assembly that is disposed between the end member and the damper rod. Typically, the seal assembly will form a substantially fluid-tight seal with both the end member and the damper rod, and will be fluidically disposed between the spring chamber and the damper rod bushing. As result, conventional damper rod bushings are designed for use in fluid isolation with respect to the pressurized gas within the spring chamber of the gas spring assembly. Accordingly, conventional damper rod bushings are constructed for use in isolation from pre-load forces associated with exposure to the pressurized gas within the spring chamber of the gas spring assembly. As such, direct exposure of known damper rod bushings to pressurized gas from the spring chamber can have an undesirable influence on the performance and operating characteristics of conventional damper rod bushings.
As described above, conventional damper rod bushings are typically used together with a seal assembly that fluidically isolates the damper rod bushing from the pressurized gas of the spring chamber of the gas spring. Notwithstanding the common usage and overall success of conventional designs, it is believed desirable to develop damper rod bushing constructions suitable for use without a sealing assembly, such as may provide for improved packaging and reduced mounting envelopes, reduced weight, reduced costs of manufacture and/or assembly and/or such as may otherwise advance the art of gas spring and damper devices.